Apparatus and process for casting steel ingots



July 21, 1925.

- M. SAUNDERS APPARATUS AND PROCESS FOR CASTING STEEL INGOTS Filed Jan. 3, 1924 I JHVCTLM 1 6226640 615 69 2/ M 53 Patented July 21, 1925.

MALCOLM SAUNDERS, F GANTON, OEIO.

APPARATUS AND PROCESS FOR CASTING STEEL INGOTS.

Application filed January 8, 1924. Serial No. 684,119.

' lowing is a specification.

This invention relates to the casting of steel ingots and has more especial reference to an apparatus and process for perfecting the ingots and eliminatin the formation of defects known as piping, which commonly occur in the pouring of ingots due to the gas bubbles which rise through the molten metal and to the shrinkage of the metal.

It is well known that these defective portions of the ingots must be chipped or ground out when the steel is-rolled resulting in a loss of from five per cent (5%) to as high as forty per cent (40%) of the steel and requiring considerable time and labor which necessarily increases the cost of the production of steel.

It is well known common practice in steel mills to use brick tops or hot to supon the ingotmolds in an attempt to ehminate these defects in the ingots, but even with the use of such devices, only a portion of the impressions in the ingots is avoided, and steel rolled from the two ends of an ingot formed in the ordinary manner will have difierent characteristics.

The objects of the present invention are to rovide an-apparatus and process for casting ingots, which includes a hollow plunger adaptedto be supported at the upper end of an ingot mold and having an'upwardly tapered interior designed to have a wedgingaction upon the upper end of the ingot while it is still hot, in order to'eliminate any piping in the same, a pair of perforated plugs, one of which is preferably formed of fire clay or other refractory material and the other of cast iron, being placed upon the top of thepoured metal within the hollow plunger to permit the gas to pass .through the same.

-The above and other objects may be attained by constructing the apparatus in the Figure 1 1s a vertlcal sectional view of I the an ingot mold provided with the improved plunger, showing the same in the initial position ust after the steel has been poured; Fig. 2, a simllar view showing the same after the plunger has been lowered;

Flg. 3, a View similar to Figs. 1 and 3,

; showing a portion of the striptping machine in the act of removing the from the mold;

Fig. 4:, a bottom plan view of the brake band;

Fig. 5, an enlarged sectional view through a portion of the hollow plunger and ingot mold, showing the brake band operatlng lever 1n position to lock the band around plunger;

Fig. 6, a detail sectional view on the line 6-6 Fig. 5;

Fig. 7, a plan view of the safety plug;

Fig. 8, a similar view of the fire brick plug; and

"Fig. 9, a vertical sectional view of a slightly modified form of the apparatus adapted for large top molds.

Similar numerals refer to similar parts throughout the drawing.

Referring to the construction shown in Figs. 1 to 8 inclusive, the ingot mold 1 may be of any usual large bottom construction. either plain or fluted.

ished ingot The interior of the upper end portion of the mold indicated at 2 is round, and preferably machined for a sufiicient distance from the top to accommodate the hollow plunger 3 which may be formed of cast iron and is machined to provide a sliding fitoi the same within the upper end of the mold. I

This plunger is provided with the central, upwardly tapered opening 4 and with the enlarged annular head 5 at its upper end upon which" are provided lugs 6 for raising or lowering the plunger. The lower edge of the plunger is bevelled or rounded as shown at 6 to provide easy passage. of the same through the metal and] also to give the proper shape to the ingots.

' The plunger may be held in raised position, as shown in Fig. 1, by means of a brake band which may be in the form of a two part steel ring, as shown in Fi 4. The two halves of the-ring may be in d together at one end as shown at 8, t e free ends being provided with the angular porformed upon the portion 10.

A bolt 12 is extended through the angular portions 9 and 10 and beneath the web 11. a heavy coil spring 13 being located around the same between the side of the angular portion 10 and the head 15 of the bolt, tendmg to urge thehalves of the brake band toward each other. 10

The lever 16 may be pivoted upon the bolt 12 and provided with the wedge portion 17. intermediate its extremities, arranged to separate the halves of the ring against the action of the spring 13, when it is desired to release the tension upon the plunger.

In operating the apparatus to pour an ingot, the plunger is raised into the position shown in Fig. 1, the lever 16 of the brake band being raised to permit the brake band to tightly grip the plimger and hold the same supported in this position.

The steel is then poured into the ingot and up into the plunger to about the height shown in Fig. 1. The perforated plug 18, which may be of fire brick or similar material, or which may be in the form of a mat of straw or the like, is then inserted through the top of the plunger and placed upon the top of the molten steel and the perforated safety plug 19 which may be of CitStlI'OIl, steel or the like, is then inserted through the open upper end of the plunger, a wire 19 being preferably looped through the perforations of the plug, whereby the same may be pulled to the top of the opening and held wedged therein by twisting the wire around a small rod 19 The plug 18 may be heated before it is placed upon. the metal, to assist in retaining the heat at the top of the ingot.

It will be noted that each of these plugs is provided upon the diametrically opposite sides with the fiat faces 20 to permit their being easily inserted through the reduced top of the plunger and in placing these plugs upon the top of the molten steel, the fiat faces of the two plugs should be stag gered as shown in the drawings, in order to completely close the plunger, excepting for the perforations in the plungers, which permit the gases from the molten steel to escape through the top of the plunger.

The metal will immediately start to freeze around the outside, checking the gases from escaping. The brake band is then released by throwing the lever down, the wedge 17 thereon forcing the halves of the ring apart, against the action of the spring 13, permitting the plunger, which, of course, will be of considerable weight, to descend in the manner shown in Fig. 2, the conical interior of the plunger forcmg in the sides of the ingot at the top thereof, breaking the frozen crust upon the ingot and closing the central portion of the ingot before the same has hardened, an equal pressure being exerted upon all sides -of the ingot, forcing the metal toward the center and the gases out of the top, thus removing'any piping which may otherwise form injthe lngot.

After the ingot has cooled, it may be removed from the mold by the usual stripper machine, indicated generally at 21, the jaws 22 thereof engaging the lugs at the top of the ingot mold in the usual manner, while the plunger 23 is moved down through the open plunger and forces the ingot through the open bottom of the mold.

A modification of the. invention is shown in Fig. 9, in which a large top mold 1 is provided with the improved apparatus. A collar 24 provided with a depending flange 25 at its inner edge, is placed upon the top of the mold, the flange 25 extending down into the top thereof. This collar receives the open plunger 3 which may be of the same construction as above described and operated in the same manner.

It will be seen that steel poured in accordance with the above described process, and using an apparatus of the character described and illustrated, will be free from piping. Since the open plunger has considerable weight, it will be evident that as the ingot is cooling, an even pressure will be applied to the sides of the cooling steel at the upper portion thereof, squeezing the mass toward the center and eliminating any piping while the perforations in the plugs will permit the gases to escape during the time the hot steel is being squeezed together, thus producing a solid mass and eliminating the imperfections in the finished ingot.

It will also be seen that this device also accomplishes the purposes of the usual brick top as it will retain the heat of the ingot at the top until the bottom of the ingot has cooled sufiiciently to solidify, while at the 'same time sulficient pressure is exerted upon the sides of the upper portion of the ingot to weld the same into a solid mass.

It will of course be understood that when the improved apparatus is used upon large top molds, it will be necessary to remove the plunger and collar before the ingot can be stripped from the mold.

I claim i 1. The improved method of forming ingots from molten metal which consists in retaining the heat in the upper ortion of the ingot until the lower portion has soliditied and applying sufficient downward pressure to the top and sides of the upper portion of the ingot to weld all portions of the ingot into a solid mass.

2. The improved method of forming ingots from molten metal whichconsists in downwardly compressing the top and sides of the upper portion of the ingot while the same is st111 hot and in covering the top of the ingot with a perforated cover of refractory material to permit the escape of gases during said compression.

3. The improved method of forming ingots from molten metal which consists in lowering a plunger having a conical central opening around the upper portion of the metal to exert an equal pressure upon all sides and the top of the metal to press the same toward the center.

4. An ingot casting apparatus including an'open top mold, a plunger slidably fitting within the top of the mold and having an upwardly tapered, central opening, and a brake band resting upon the top of the mold and engaging the plunger to hold the same in raised position.

5. An ingot casting apparatus including an open top mold. a plunger slidably fitting within the top of the mold and having an upwardly tapered, central opening the lower end of which is ofnsubstantially the same cross sectional area as the mold, and means for holding the plunger in any desired vertical position.

6. An ingot casting apparatus including an open top mold, a plunger slidaloly fitting within the top of the mold and having an upwardly tapered, central opening, and a brake band comprising a two part hinged ring surrounding the plunger and resting upon the top of the mold, and spring means for drawing the ring together around the plunger.

7. An ingot casting apparatus including an open top mold, a plunger slidably fitting within the top of the mold and having an upwardly tapered, central opening, a brake band comprising a two part hinged ring surroundingthe plunger and resting upon the top of the mold, spring means for drawing the ring together around the plunger, and means for releasing the brake band to permit the plunger to descend;

8. An ingot casting apparatus including an open top mold, a plunger slidably fitting within the top of the mold and having an upwardly tapered, central opening, a brake band comprising a two part hinged ring surroundin the plunger and resting upon the top of t e mold, spring means for drawing the ring together around the plun er, and means for releasing the brake ban to permit the plunger to descend, said releasing means being designed to permit any desired drop of the plunger.

9. An ingot casting apparatus including an open top mold, a plunger slidably fitting within the top of the mold and having an upwardly tapered central opening and means for detachably holding the plunger in any desired vertical position, the en gaging faces of the mold and plunger being finished to provide a close fit in order to prevent molten metal from entering be tween the mold and plunger and means for permitting gases to escape from the ingot during the operation of the plunger.

10. An ingot casting apparatus including an open top mold, the inner, upper edge of which is beveled and an open plunger slidably fitting within the top of the mold.

11. An ingot casting apparatus including an open top mold, a plunger slida-bly. fitting within the top of the mold and having an upwardly tapered, central opening, and a perforated plug adapted to be placed through the top .of the plunger upon the metal.

12. An ingot casting apparatus including an 0 en top mold. a plunger slidably fitting within the top of the mold and having an upwardly tapered, central opening, and a beveled lower edge, and means for holding the plunger in any desired vertical position.

13. An ingot casting apparatus including an open top mold. a plunger slidably fitting within the top of the mold and having an upwardly tapered, central opening, a perforated fire clay plug adapted to be placed through the top of the plunger upon the metal and a perforated metal plug adapted to be placed through the top of the plunger and supported therein.

14. An ingot casting apparatus including an open top mold, and means at the top of the mold for wedging the upper portion of a glot ingot downward uniformly upon all s1 es.

In testimony that I claim the above, I have hereunto subscribed my name. Y

MALCOLM SAUNDERS. 

